Abstract: The effect of soil water stress on the morphological and physiological characteristics of the seedling stage of the soybean had been studied. The results showed that soybean leaf photosynthesis rate, transpiration rate and stomatal conductance had a downward trend as drought stress increased. The chlorophyll content and leaf water content showed the low-high-low trend with the time course of stress. There were large differences in dry matter accumulation among treatments. At the initial stage of drought stress, the effect of stress on dry matter partitioning ratio was very little, however, as stress increased, the difference increased too. As stress became stronger and advanced, proline content increased significantly, specifically under severe water stress.

Key words: water stress, seedling stage, soybean, physiological and morphological characteristics

摘要： 对土壤逐步干旱下大豆幼苗形态特征和生理生态特征的变化研究表明:随着胁迫强度的增加,大豆苗期的光合速率、蒸腾速率、气孔导度降低,且相互之间呈显著正相关;随着胁迫时间的延长,叶绿素含量和叶片含水量呈低-高-低的变化趋势;在胁迫初期,对干物质分配率的影响很小,随着胁迫时间的增加,差异越来越大;随着干旱胁迫天数和强度的增加,游离脯氨酸含量呈逐渐递增的趋势,尤其是重度胁迫下积累能力更强。

关键词: 干旱胁迫, 苗期, 大豆, 生理和形态特征